Coiled Member Measuring Device

ABSTRACT

A coiled member measuring device includes a main frame fixedly anchored in relation to the outer casing or the coiled member handling device of a well and an inner housing supported by the main frame for unrestricted lateral movement in at least two different directions transverse to one another and in a common plane oriented perpendicularly to an axial direction of the outer casing. Followers in the inner housing surround an axial passage receiving a coiled member such as coiled tubing or continuous rod therethrough. Two adjacent followers are supported in a V-shaped pattern for sliding movement diametrically opposite a third remaining follower. Sensors associated with the followers permit determination of overall circumference and length of the coiled member.

This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 61/553,605, filed Oct. 31, 2011.

FIELD OF THE INVENTION

The present invention relates to a measuring device suitable for connection in series between the outer casing of a wellbore and a coiled member handling device such as a coiled tubing or continuous rod injector head, and more particularly the present invention relates to a measuring device including one or more counting sensors associated with follower wheels for measuring length of the coiled member and a linear sensor or sensors associated with radial position of the follower wheels for measuring an overall circumference of the coiled member as an indicator of wear.

BACKGROUND

When injecting coiled tubing into a hydrocarbon production well, or when conveying coiled rod into or out of a well, it is desirable to monitor the diameter of the coiled member to evaluate the roundness, ovality or overall circumference as an indicator of wear or deformation of the member which can lead to leaks or more serious accidents. More particularly, the measurement of overall circumference is desirable to detect deformations in the coiled rod which can lead to premature failure of the string and cause remedial workovers increasing cost, lost production and more down time. Also for coiled tubing, it is important to maintain a certain degree of roundness in order to maintain lift capabilities of the velocity string for dewatering gas wells. As the coil begins to drift from roundness and becomes oval or egg shaped, the effectiveness decreases as friction factors increase due to the change in shape.

Some prior art methods of checking overall circumference and/or rod wear at the well head include using calipers or box wrenches while rods are being pulled out of the well. These methods can be quite dangerous as being in contact with moving rods can lead to getting hung up on the rods leading to injury. These methods are also very time consuming and subject to operator error.

Various devices related to assessing ovality and overall circumference are described in the following United States patents. U.S. Pat. No. 7,458,267 by McCoy, U.S. Pat. No. 5,335,422 by Ferguson, U.S. Pat. No. 6,862,900 by Lam et al., U.S. Pat. No. 5,867,275 by Curtis, Jr. et al., and U.S. Pat. No. 4,240,206 by Baresh et al. None of these prior art devices for measuring overall circumference have a suitably robust construction for use in various applications within the oilfield industry, nor are any of the prior devices suited for use in series below a tubing injector and stripper, or below a coiled rod gripper, where the coiled member is substantially stripped of debris and is already stretched for optimal measuring.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising:

a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device;

an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage;

a plurality of followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage which arranged to receive the coiled member;

at least one of the followers being supported on the inner housing by a sliding member such that said at least one of the followers is supported for linear sliding movement in a generally radial direction relative to the axial passage to vary the overall circumference of the axial passage;

at least one sensor associated with the followers for sensing a prescribed characteristic of the followers; and

a processor arranged to determine at least one of an overall circumference or a length of the coiled member in response to the prescribed characteristic sensed by said at least one sensor;

the inner housing being supported by the main frame for unrestricted lateral movement in at least two different directions transverse to one another and in a common plane oriented perpendicularly to an axial direction of the axial passage.

By supporting the inner housing in an unrestricted manner in a plane perpendicular to the coiled member, the entire assembly of followers about the coiled member are free to move generally radially with the coiled member relative to the wellbore so that misalignments of the coiled member with the outer casing do not erroneously affect measurements of the overall circumference. Also, the followers can be more easily engaged about the coiled member with a substantially even pressure on all sides so that when the followers also comprise counting wheels, a more consistent count can be realised from all of the followers.

Preferably at least one of the followers comprises a wheel and said at least one sensor comprises a counting sensor arranged for counting rotations of the wheel, the processor being arranged to determine a length of the coiled tubing member in response to the rotations counted by the counting sensor.

Preferably said at least sensor comprises both a linear sensor and a counting sensor.

The linear sensor may be arranged to measure a linear position of at least one of the followers in the radial direction. In this instance the processor is arranged to determine an overall circumference of the coiled member in response to the linear position measured by the linear sensor.

The counting sensor may be arranged for counting a length of the coiled member. In this instance the processor is arranged to associate the overall circumference measurement with the length determined by the counting sensor.

The processor may be further arranged to calculate and record the overall circumference measurement at a plurality of locations along a length of the coiled member and to associate the length of the coiled member with the overall circumference measurement for each of the plurality of locations along the length of the coiled member.

There may be provided a display arranged to be located in proximity to a wellhead of the well in which the processor is arranged to continuously calculate the overall circumference measurement and display the calculated overall circumference measurement on the display as the coiled member is conveyed relative to the well.

When the processor is arranged to continuously calculate the overall circumference measurement as the coiled member is conveyed relative to the well, preferably there is provided an alarm arranged to indicate an alarm condition when the overall circumference measurement outside of a prescribed range of acceptable overall circumference measurements.

In a preferred embodiment each follower comprises a wheel and the sensor comprises both a linear sensor to determine a linear position of the follower in a respective radial direction and a counting sensor for counting rotations of the wheel. In this instance the processor is preferably arranged to determine both an overall circumference of the coiled member in response to the linear position determined by the linear sensor associated with said at least one of the followers and a length of the coiled member in response to the rotations counted by the counting sensor associated with said at least one of the followers.

Preferably some of the followers are supported for sliding movement relative to the housing on the sliding member and one other follower is supported on the inner housing diametrically opposite from the sliding member.

The linear sensor is preferably associated with the sliding member so as to be arranged to measure a linear position of the respective followers on the sliding member in the respective radial direction of the sliding member so that the processor can determine an overall circumference of the coiled member in response to the linear position measured by the linear sensor relative to the other follower.

In the preferred embodiment, the plurality of followers comprise a set of three followers in which each follower comprises a wheel arranged for rolling movement along the coiled member about a respective wheel axis such that all three wheel axes lie in a generally common plane perpendicular to the axial direction. In this instance two adjacent ones of the followers may be commonly supported on the inner housing by the sliding member such that the respective wheel axes are oriented in a generally V-shaped configuration, while the other follower may be supported in fixed relation to the inner housing diametrically opposite from an apex of the V-shaped configuration so as to be arranged to vary the overall circumference of the axial passage as the sliding member is displaced relative to the inner housing.

The sliding member preferably comprises a plate member supported at opposing sides thereof for sliding movement along opposing sides of the inner housing.

The main frame preferably comprises a main housing including:

an upper mounting collar and a lower mounting collar in concentric alignment with one another at opposing top and bottom ends of the main housing respectively, the upper and lower mounting collars being arranged for connection in series with the outer casing so as to be arranged to receive the coiled member conveyed therethrough; and

a support frame connected between the upper and lower mounting collars such that the upper and lower mounting collars are spaced apart in an axial direction of the collars.

Preferably the inner housing is arranged to be supported on the support frame of the main housing between the upper and lower mounting collars such that the axial passage is aligned with the upper and lower mounting collars.

The support frame may comprise an upper plate member integrally joined to the upper mounting collar and a lower plate member integrally joined to the lower mounting collar in which the lower plate member is parallel and spaced below the upper plate member so as to be arranged to receive the inner housing therebetween and such that the inner housing is readily slidably removable from the main housing.

The support frame may further include a plurality of posts spanning in the axial direction between the upper plate member and the lower plate member along opposing sides of the plate members so as to be arranged to receive the inner housing between the posts at the opposing sides of the plate members.

The inner housing preferably comprises a top wall and a bottom wall which are parallel and spaced apart from one another such that the followers are received therebetween in which the top and bottom walls include respective top and bottom apertures therein in alignment with the axial passage through the inner housing.

Preferably the inner housing also comprises a plurality of side walls spanning between the top and bottom walls about a full periphery thereof to enclose the followers within an interior of the inner housing.

According to a second aspect of the present invention there is provided a measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising:

a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device;

an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage;

a set of three followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage, each follower comprising a wheel arranged for rolling movement along the coiled member about a respective wheel axis such that all three wheel axes lie in a generally common plane perpendicular to an axial direction of the axial passage;

two adjacent ones of the followers being commonly supported on the inner housing such that the respective wheel axes are oriented in a generally V-shaped configuration for linear sliding movement in a generally radial direction of the axial passage relative to the remaining follower which is diametrically opposite from an apex of the V-shaped configuration so as to be arranged to vary the overall circumference of the axial passage;

at least one sensor associated with the followers for sensing a prescribed characteristic of the followers; and

a processor arranged to determine at least one of an overall circumference or a length of the coiled member in response to the prescribed characteristic sensed by said at least one sensor.

The arrangement of two follower wheels supported in a V-shaped configuration on one sliding member permits three followers to engage the coiled member at substantially evenly circumferentially spaced positions with only one linear sensor being required to evaluate the overall circumference as gauged by the three circumferentially spaced follower wheels to more readily indicate potential wear of the coiled member.

According to a third aspect of the present invention there is provided a measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising:

a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device;

an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage;

a set of three followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage, each follower comprising a wheel arranged for rolling movement along the coiled member about a respective wheel axis;

at least one of the followers being supported on the inner housing by a sliding member for linear sliding movement in a generally radial direction of the axial passage relative to the other followers so as to be arranged to vary the overall circumference of the axial passage;

a linear sensor associated with the sliding member of said at least one of the followers so as to be arranged to determine a linear position of the sliding member in the respective radial direction;

a counting sensor associated with the wheels of at least one of the followers so as to be arranged for counting rotations of the wheel; and

a processor arranged to determine an overall circumference of the coiled member in response to the linear position determined by the linear sensor associated with said at least one of the followers and arranged to determine a length of the coiled member in response to the rotations counted by the counting sensor associated with said at least one of the followers.

By combining the length and overall circumference measurements with a single set of followers, the measuring device is efficient in construction and also allows for recording a log of the wear measurement as it varies along the length of the coiled member conveyed relative to the well. In this instance, if any problem areas are detected by the wear measurement, the location of the problem along the length of the coiled member can be readily identified for later repair or replacement as may be desired.

One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the measuring device;

FIG. 2 is a top plan view of the measuring device according to FIG. 1;

FIG. 3 is a side elevational view of the measuring device according to FIG. 1;

FIG. 4 is an end elevational view of the measuring device according to FIG. 1;

FIG. 5 is a perspective view of the main housing of the measuring device according to FIG. 1 with the inner housing shown removed;

FIG. 6 is a perspective view of a top side of the inner housing with a top plate shown removed;

FIG. 7 is a top plan view of the inner housing; and

FIG. 8 is a perspective view of a bottom side of the inner housing with a bottom plate shown removed.

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION

Referring to the accompanying figures there is illustrated a coiled member measuring device generally indicated by reference numeral 10. The measuring device 10 is particularly suited for oil or gas well operations involving injecting or extracting a coiled member 12, for example coiled tubing or continuous rod, for measuring overall circumference or roundness of the coiled member as an indicator of wear and for counting the depth which the coiled member is inserted into or extract from the well in either pressurized or non-pressurized locations.

The device 10 is typically used in an oil or gas well having an outer casing terminating at a top end by a casing flange which may connect a master valve, a flow tee having an auxiliary valve and a primary well control which includes a stripper and a blow out preventer (BOP) as components of the wellhead. A coiled member handling device is connected above the primary well control. In the instance of the coiled member comprising coiled tubing, the handling device typically comprises a coiled tubing injector head for injecting the tubing into the well. In the instance of a coiled member comprising continuous rod, the handling device typically comprises a gripper unit arranged to inject or extract the rod relative to the well.

The measuring device 10 comprises a main frame in the form of a main housing 20 which is typically mounted in series with the outer casing of the well bore below the gripper unit of the handling device but above the BOP and stripper. The positioning of the measuring device between the handling device and the wellhead is advantageous as this is the straightest position for the measuring device 10 and it accounts for stretching of the coiled member suspended from the handling device.

The main housing 20 generally comprises an upper mounting collar 22 at the top end of the main housing and a lower mounting collar 24 at the bottom end. Each of the mounting collars is arranged for mating connection in series with wellhead components above and below the main housing at the top of the casing string as described above such that the main frame or housing is anchored in fixed relation to the outer casing and the coiled member handling device. For example, each of the upper and lower mounting collars may include suitable connecting means such as threaded connections or other suitable unions readily available in the oil field industry.

The upper and lower mounting collars are mounted in fixed relation to one another so as to be co-axially aligned in spaced apart relationship in the axial direction by a suitable support frame 26 of the main housing. The support frame is a rigid structure providing structural support between the upper and lower mounting collars such that the collars are adequately fixed in axially spaced relation.

The support frame includes an upper plate member 28 and a lower plate member 30 which are integrally joined to the upper collar and the lower collar respectively. Furthermore, each of the plate members is a generally square member mounted perpendicularly to the axial direction with the respective collar being centrally located in alignment with a respective opening through the plate member to define a through axial passage between the mounting collars of the main housing. The upper plate member is fixed adjacent the bottom end of the upper mounting collar with suitable gussets providing additional structural support therebetween. Similarly, the lower plate member is fixed to the upper end of the lower mounting collar with gussets providing additional structural support therebetween.

The upper and lower plate members are fixed parallel and spaced apart from one another by a plurality of posts 32 of the support frame. The posts are all parallel to one another and extend in the axial direction between opposing ends fastened to the upper end and lower plate members respectively. The posts are arranged in two evenly spaced rows along two respective opposing sides of the upper and lower plate members such that the remaining two intermediate sides of the upper and lower plate members remain open between respective ones of the posts 32 at the corners of the plates. Four posts are provided in each row.

The support frame 26 further comprises lift hooks 34 fixed to the top side of the upper plate member adjacent the four corners thereof. Each lift comprises enclosed eyelet welded to the top side of the plate member such that the measuring device can be readily handled by various lifting and handling equipment.

The device 10 further includes an inner housing 36 arranged to be received between the upper and lower plate members of the main housing. The inner housing also defines an axial passage extending therethrough which is arranged for alignment with the upper and lower mounting collars such that the coiled member 12 is arranged to be received through the upper and lower mounting collars and through the axial passage of the inner housing when the device is connected in series with the components at the wellhead of a wellbore. The inner housing includes various components therein arranged for engaging the coiled member as it is conveyed through the axial passage for evaluating an overall circumference of the coiled member at various locations along the length of the coiled member as well as for counting the length of the coiled member conveyed through the housing.

The inner housing includes a generally rectangular top wall 38 and a bottom wall 40 of similar shape and dimensions. The bottom wall is mounted parallel and spaced below the top wall by an overall height which is less than the space between the upper and lower plate members of the main frame to permit the inner housing to be received between the upper and lower mounting collars within the main housing. The inner housing also includes four side walls 42 connected between respective side edges of the top and bottom walls to fully enclose the various components within the inner housing for measuring overall circumference and length of the coiled member.

The inner housing has a length in a first direction which is greater than the corresponding dimension of the support frame of the main housing and a width in a second direction which is less than the width between the two rows of posts of the support frame. In this instance, the inner housing is arranged to be slidable in the first direction thereof into the support frame between the two rows of posts 32 such that the first direction corresponds approximately to the direction of the rows of posts. The width in the second direction is arranged to be less than the space between the rows of posts such that the inner housing is arranged to be readily movable in a lateral direction between the two rows of posts.

In a working position, the inner housing rests on the lower plate member of the support frame so as to be freely floating and unrestricted in movement relative to the main frame in either one of the first direction because the open ends of the support frame between the two rows of posts or the second direction because of the narrower dimension of the inner housing than the spacing between rows of posts. The inner housing is thus generally freely moveable within a plane oriented perpendicularly to the axial direction within which the first direction and second direction are located.

To assist in supporting the inner housing for sliding relative to the main housing, a plurality of sliders 45 are mounted on the top and bottom sides of the inner housing. The sliders comprise elongate strips of rigid material, for example aluminum, which are mounted to extend longitudinally in the first direction of the length of the inner housing along opposing side edges of both the top and bottom edges. The sliders 45 are fixed to the top and bottom walls to project upward and downward therefrom respectively and to define the sliding contact with the respective upper and lower plate members of the main housing. The sliders on both the top and bottom walls are arranged in longitudinally spaced apart pairs along each side edge. In this manner four sliders in a common horizontal plane are located at the four corners of the rectangular inner housing for sliding contact between each respective top or bottom wall and the respective upper or lower plate member of the main frame.

The axial passage through the inner housing is defined in part by an upper aperture 44 in the top wall of the inner housing and a lower aperture 46 in the bottom wall of the inner housing which are arranged for alignment with the passages through the upper and lower mounting collars in a working position of the inner housing within the main housing. The upper and lower apertures are generally oval in shape so as to be elongated longitudinally in the first direction of the inner housing.

The axial passage is further defined by a set of three followers 48 mounted within the inner housing at evenly spaced positions in a circumferential direction about the axial passage for engagement with the coiled tubing passing through the housings.

Two of the followers are supported on a sliding member 50 within the inner housing which is arranged for linear sliding movement longitudinally in the first direction of the housing relative to the inner housing.

A third one of the followers is supported by a pair of support plates 51 rotatably supporting the follower therebetween. The support plates are in turn supported on a cross plate 53 which is perpendicular to the longitudinal first direction to span between two opposing side walls of the inner housing and to span a full height between the top and bottom walls. The support plates 51 support the respective follower 48 between the upper and lower apertures defining the axial passage at a location diametrically opposed from the sliding member 50 in line with the sliding axis thereof. An enclosed area is defined between the cross plate 53 and the end wall at the corresponding first end 52 of the housing for receiving various measuring equipment as described in further detail below.

The third follower 54 supported by the support plates 51 comprises a wheel rotatable about an axis within a plane perpendicular to the axial passage while also being perpendicular to the sliding direction. The follower 54 projects radially inwardly into the axial passage defined by the apertures in the top and bottom walls so as to be suitable for rolling engagement with the coiled member inserted through the axial passage.

The sliding member 50 comprises a generally planar body in the form of a flat plate mounted parallel to the top and bottom walls. A pair of tracks 66 are mounted along a portion of the two opposed side walls of the inner housing such that opposing longitudinally extending side edges of the flat plate forming the body of the second sliding member are received in respective ones of the tracks for linear sliding movement in the sliding direction.

The sliding member 50 supports a first follower and a second follower thereon such that the two followers 68 comprise respective wheels which are rotatable about respective axes lying in a common plane with the other wheel axis but in a V-shaped configuration relative to one another. The common plane is oriented perpendicularly to the axial direction and the V-shaped configuration of the two wheel axes is oriented such that the apex is pointed outward diametrically opposite the first follower 54 symmetrically about the sliding axis.

The wheels are supported on the flat plate forming the body of the sliding member by suitable shaft support blocks 70 at axially opposed ends of each wheel. The support blocks 70 are suitably fastened to the planar body with appropriate fasteners for permitting some positional adjustment therebetween. The wheels are fastened along corresponding inner edges of a V-shaped recess 72 formed at the inner side of the plate forming the sliding member such that the recess in the plate is aligned with the axial passage. The wheels project inwardly beyond respective inner edges of the V-shaped recess such that the plate member does not interfere with engagement of the two second followers 68 with the coiled member inserted through the inner housing.

The second sliding member includes a piston shaft 74 fixed to the inner end and extending outward in the sliding direction towards a cylinder housing 76 mounted in fixed relation at the second end of the inner housing. A support plate 78 is also provided at an intermediate location between the sliding member adjacent the axial passage and the second end of the housing. The support plate is perpendicular to the sliding direction and provides support to the cylinder housing 76 which spans between the support plate 78 and the end wall at the second end of the housing. The cylinder housing of the second sliding member provides a biasing force to urge the sliding member inward in the sliding direction towards the opposing third follower such that the first and second followers 68 are urged into engagement with the coiled member.

The second sliding member includes a linear sensor 80 in association therewith. The linear sensor 80 includes a measuring rod 82 for abutment with a corresponding portion of the second sliding member body in the working position. The measuring rod is parallel to the shaft and sliding direction for sliding movement together with the sliding member relative to the inner housing in the working position by a biasing spring urging the rod into engagement towards the sliding member.

A position measuring device 84 measures a linear position of the first and second followers 68 in the sliding direction relative to the inner housing and the third follower 54 by measuring sliding movement of the measuring rod with the sliding member relative to the inner housing. The measuring rod 82 is a plunger relative to a surrounding cylinder of the position measuring device such that the rod 82 is telescopic relative to the position measuring device 84 and the rod is biased into an extended position protruding therefrom into abutted engagement with the corresponding portion of the sliding member.

The position measuring device 84 is mounted within an enclosed space at the first end of the inner housing between the cross plate 53 and the end wall at the first end of the inner housing. A secondary enclosure 85 is provided within the enclosed spaced to enclose electronic components which receive sensed conditions from various sensors of the device 10 to permit the measured characteristics to be relayed to an external controller described in further detail below.

The arrangement of one follower diametrically opposite from two other followers symmetrical about the sliding axis of a sliding member provides three rolling followers at circumferentially spaced positions about the axial passage for corresponding circumferentially spaced contact with the coiled member received through the axial passage. Using the sensed linear position of the sliding member, the points of contact of the three followers with the coiled member can be determined for estimating the overall diameter and/or overall circumference of the coiled member.

The measuring device 10 includes a suitable processor which may be integrally supported within the inner housing or may be provided as components of a separate controller connected to the sensors by a suitable communicating means, for example a cable or by wireless means. The processor calculates the overall circumference based on the linear positions of the two sliding members to compare the overall circumference to a lower circumference limit which indicates excessive wear of the coiled member.

Each wheel of the three followers also includes embedded magnets at predetermined circumferential spaced positions for being detected by a counting sensor 60 associated therewith for counting the rotations of the respective wheels. The processor also communicates with the counting sensors for determining the length of the coiled member conveyed through the axial passage by multiplying the number of rotations of the wheels by the circumference of the respective wheels. In this manner, each wheel calculates the length independently of the others, based on its respective number or rotations. The three lengths can be averaged to determine the overall length. In some instances, if one of the counts is determined to be different than the others by a prescribe threshold, that count can be excluded from the others in determining the average when measuring length.

By associating the counting sensors with the wheels of the followers whose linear position is also measured, the same followers are effectively used for determining the conveyed length of coiled member by rolling contact with the coiled member as well as gauging the wear of the coiled member along its length by calculating overall circumference or diameter of the member.

The processor is typically arranged to continuously calculate the overall circumference measurement as the coiled member is conveyed relative to the well. In this instance, the processor may also include an alarm which is arranged to alert users and to indicate an alarm condition when the overall circumference measurement falls outside of a prescribed range of overall circumference measurements. In particular, the overall circumference is compared to a lower limit to determine the alarm condition as the lower limit is an indication of excess wear.

The measuring device may also include a display arranged to be located in proximity to the wellhead of the well which includes the controller and processor components therein. In this instance the processor may be arranged to display the calculated overall circumference measurement in real time as the circumference is continuously calculated at numerous points along the length of the coiled member as the member is conveyed through the measuring device 10. The controller may include a suitable memory for recording the varying overall circumference measurement and associating each overall circumference measurement at a particular location along the length of the coiled member. By associating the length of the coiled member with the overall circumference measurement for each of a plurality of locations along the length of the coiled member, specific areas of concern where there may be excess wear can be subsequently located and attended to with proper maintenance.

Access to the inner housing is provided by a suitable hinged panel 90 forming a portion of the top wall locating the top opening therein. The hinged panel spans a full width of the top wall in the lateral direction and spans in the longitudinal direction and the area within which the second sliding member overlaps throughout its range of movement in the sliding direction. The hinged panel thus overlaps the second followers on the second sliding member as well as the first follower at the inner end of the elongate body of the first sliding member. The hinged panel is simply hinged along one end to the remainder of the top wall while including suitable fastening at the opposing end to selectively fix the panel in a closed condition in use.

A corresponding access panel 92 is also provided in the bottom wall which is approximately the same size as the hinged panel in the top wall in alignment therewith and thus locates the lower opening of the axial passage therein. The access panel in the bottom wall is joined between two respective removable portions 94 of the side walls of the inner housing such that the access panel 92 can be removed with the two removable portions of the side walls together. The removable portions of the side walls 94 locate the tracks of the second sliding member thereon such that the planar body of the second sliding member is removable with the tracks and the access panel with suitable threaded fasteners for maintenance and the like.

In use, the followers are fully enclosed within the interior of the inner housing about the axial passage through the inner housing. A biasing force is provided to the sliding member such that inner housing substantially centers itself at the axial passage about the coiled member received therethrough by permitting sliding of the inner housing relative to the main frame. In the event that the coiled member deviates from the longitudinal center of the axial passage through the upper and lower mounting collars of the main housing, the inner housing will tend to deviate together with the coiled member in both the longitudinal first direction and the lateral second direction so that deviation of the coiled member from the center of the upper and lower mounting collars as it is conveyed relative to the borehole will not erroneously affect the measurements by the counting sensors and the linear position sensors.

When initially injecting a coiled member into well, it is desirable to fix the inner housing relative main frame such that the axial passage defined by apertures and followers aligned with the axial passage of the upper and lower mounting collars of the main frame. This is permitted by provided a pair of anchor members 100 protruding laterally outward from opposing sides of the inner housing towards one end of the housing. In the illustrated embodiment, the anchor members comprise eyelets which are integrally formed with respective ones of the sliders 45. Apertures in the anchor members are arranged for alignment with corresponding apertures in an anchor plate 102 secured along a corresponding edge of the bottom plate member 30 of the main housing. When anchor pins are inserted through aligned apertures in the anchor members 100 on the inner housing and in the anchor plate 102 respectively, the inner housing is effectively fixed in relation to the main frame to maintain alignment of the axial passage defined by the followers with the axial passage defined by the upper and lower mounting collars. Once the coiled member has been initially inserted through the device 10, the anchor pins are removed such that the inner housing is supported by the main frame for unrestricted lateral movement in at least two different directions transverse to one another and in a common plane perpendicularly to the axial direction of the axial passage.

The cylinder housing 76 associated with the sliding member 50 is charged with air to provide the biasing force to maintain engagement of the first and second followers. During the use of the device 10, the cylinder can be recharged with air as may be required to maintain a suitable biasing force on the sliding member. A pressure gauge 104 is mounted externally at the second end of the housing at the outer end of the cylinder 76 to externally monitor the pressure of the air charging the cylinder. If more pressured air is required to charge the cylinder, an input valve 106 communicates with the cylinder and permits connection of a suitable source of air under pressure thereto when required.

In further embodiments, the third follower may be supported on a second sliding member diametrically opposite from the sliding member supporting the first and second followers thereon. The second sliding member in this instance would similarly include a cylinder to apply a biasing force urging the third follower radially inwardly into engagement with the coiled member. A linear position measured by a linear position sensor associated with the second sliding member would then also be used together with the linear position of the first sliding member in the calculation of the ovality or circumference of the coiled member.

Since various modifications, can be made in my invention as herein above described, and many apparently other widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. 

1. A measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising: a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device; an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage; a plurality of followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage which arranged to receive the coiled member; at least one of the followers being supported on the inner housing by a sliding member such that said at least one of the followers is supported for linear sliding movement in a generally radial direction relative to the axial passage to vary the overall circumference of the axial passage; at least one sensor associated with the followers for sensing a prescribed characteristic of the followers; and a processor arranged to determine at least one of an overall circumference or a length of the coiled member in response to the prescribed characteristic sensed by said at least one sensor; the inner housing being supported by the main frame for unrestricted lateral movement in at least two different directions transverse to one another and in a common plane oriented perpendicularly to an axial direction of the axial passage.
 2. The device according to claim 1 wherein at least one of the followers comprises a wheel and said at least one sensor comprises a counting sensor arranged for counting rotations of the wheel, the processor being arranged to determine a length of the coiled tubing member in response to the rotations counted by the counting sensor.
 3. The device according to claim 1 wherein said at least sensor comprises a linear sensor arranged to measure a linear position of at least one of the followers in the radial direction, the processor being arranged to determine an overall circumference of the coiled member in response to the linear position measured by the linear sensor.
 4. The device according to claim 3 wherein there is provided a counting sensor arranged for counting a length of the coiled member and wherein the processor is arranged to associate the overall circumference measurement with the length determined by the counting sensor.
 5. The measuring device according to claim 3 wherein the processor is arranged to calculate and record the overall circumference measurement at a plurality of locations along a length of the coiled member and to associate the length of the coiled member with the overall circumference measurement for each of the plurality of locations along the length of the coiled member.
 6. The measuring device according to claim 3 wherein there is provided a display arranged to be located at a wellhead of the well and wherein the processor is arranged to continuously calculate the overall circumference measurement and display the calculated overall circumference measurement on the display as the coiled member is conveyed relative to the well.
 7. The measuring device according to claim 3 wherein the processor is arranged to continuously calculate the overall circumference measurement as the coiled member is conveyed relative to the well and wherein there is provided an alarm arranged to indicate an alarm condition when the overall circumference measurement outside of a prescribed range of acceptable overall circumference measurements.
 8. The device according to claim 1 wherein each follower comprises a wheel, wherein said at least one sensor comprises a linear sensor associated with at least one of the followers so as to be arranged to determine a linear position of the follower in a respective radial direction and a counting sensor associated with the wheels of at least one of the followers so as to be arranged for counting rotations of the wheel, and wherein the processor arranged to determine both an overall circumference of the coiled member in response to the linear position determined by the linear sensor associated with said at least one of the followers and a length of the coiled member in response to the rotations counted by the counting sensor associated with said at least one of the followers.
 9. The device according to claim 1 wherein some of the followers are supported for sliding movement relative to the housing on the sliding member and one other follower is supported on the inner housing diametrically opposite from the sliding member.
 10. The device according to claim 9 wherein said at least one sensor includes a linear sensor associated with the sliding member so as to be arranged to measure a linear position of the respective followers in the respective radial direction of the sliding member and wherein the processor is arranged to determine an overall circumference of the coiled member in response to the linear position measured by the linear sensor relative to the other follower.
 11. The device according to claim 9 wherein the plurality of followers comprise a set of three followers in which each follower comprises a wheel arranged for rolling movement along the coiled member about a respective wheel axis such that all three wheel axes lie in a generally common plane perpendicular to the axial direction and wherein two adjacent ones of the followers are commonly supported on the inner housing by the sliding member such that the respective wheel axes are oriented in a generally V-shaped configuration and the other follower is supported in fixed relation to the inner housing diametrically opposite from an apex of the V-shaped configuration so as to be arranged to vary the overall circumference of the axial passage as the sliding member is displaced relative to the inner housing.
 12. The device according to claim 11 wherein the sliding member which supports the two adjacent ones of the followers thereon comprises a plate member supported at opposing sides thereof for sliding movement along opposing sides of the inner housing.
 13. The device according to claim 1 wherein the main frame comprises a main housing, the main housing comprising: an upper mounting collar and a lower mounting collar in concentric alignment with one another at opposing top and bottom ends of the main housing respectively, the upper and lower mounting collars being arranged for connection in series with the outer casing so as to be arranged to receive the coiled member conveyed therethrough; and a support frame connected between the upper and lower mounting collars such that the upper and lower mounting collars are spaced apart in an axial direction of the collars.
 14. The device according to claim 13 wherein the inner housing is arranged to be supported on the support frame of the main housing between the upper and lower mounting collars such that the axial passage is aligned with the upper and lower mounting collars.
 15. The device according to claim 13 wherein the support frame comprises an upper plate member integrally joined to the upper mounting collar and a lower plate member integrally joined to the lower mounting collar, the lower plate member being parallel and spaced below the upper plate member so as to be arranged to receive the inner housing therebetween such that the inner housing is readily slidably removable from the main housing.
 16. The device according to claim 15 wherein the support frame includes a plurality of posts spanning in the axial direction between the upper plate member and the lower plate member along opposing sides of the plate members so as to be arranged to receive the inner housing between the posts at the opposing sides of the plate members.
 17. The device according to claim 1 wherein the inner housing comprises a top wall and a bottom wall which are parallel and spaced apart from one another such that the followers are received therebetween, the top and bottom walls including respective top and bottom apertures therein in alignment with the axial passage through the inner housing.
 18. The device according to claim 17 wherein the inner housing comprises a plurality of side walls spanning between the top and bottom walls about a full periphery thereof to enclose the followers within an interior of the inner housing.
 19. A measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising: a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device; an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage; a set of three followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage, each follower comprising a wheel arranged for rolling movement along the coiled member about a respective wheel axis such that all three wheel axes lie in a generally common plane perpendicular to an axial direction of the axial passage; two adjacent ones of the followers being commonly supported on the inner housing such that the respective wheel axes are oriented in a generally V-shaped configuration for linear sliding movement in a generally radial direction of the axial passage relative to the remaining follower which is diametrically opposite from an apex of the V-shaped configuration so as to be arranged to vary the overall circumference of the axial passage; at least one sensor associated with the followers for sensing a prescribed characteristic of the followers; and a processor arranged to determine at least one of an overall circumference or a length of the coiled member in response to the prescribed characteristic sensed by said at least one sensor.
 20. A measuring device for measuring at least one characteristic of a coiled member received within a well bore having an outer casing and a coiled member handling device connected above the outer casing so as to be arranged to convey the coiled member relative to the well bore, the device comprising: a main frame arranged to be anchored in substantially fixed relation to the outer casing and the coiled member handling device; an inner housing including an axial passage therethrough and being arranged to be supported by the main frame so as to receive the coiled member through the axial passage; a set of three followers supported on the inner housing at circumferentially spaced positions about the axial passage so as to define an overall circumference of the axial passage, each follower comprising a wheel arranged for rolling movement along the coiled member about a respective wheel axis; at least one of the followers being supported on the inner housing by a sliding member for linear sliding movement in a generally radial direction of the axial passage relative to the other followers so as to be arranged to vary the overall circumference of the axial passage; a linear sensor associated with the sliding member of said at least one of the followers so as to be arranged to determine a linear position of the sliding member in the respective radial direction; a counting sensor associated with the wheels of at least one of the followers so as to be arranged for counting rotations of the wheel; and a processor arranged to determine an overall circumference of the coiled member in response to the linear position determined by the linear sensor associated with said at least one of the followers and arranged to determine a length of the coiled member in response to the rotations counted by the counting sensor associated with said at least one of the followers. 